The instant invention relates to the jewelry art and more particularly to a method of inlaying metal in electrically non-conductive materials, such as ornamental stones.
The present method of inlaying metal in ornamental stones comprises forming narrow grooves in the stone, undercutting the grooves, i.e. making the base of the groove wider than the opening in the surface, and then mechanically forcing metal wire into the grooves using pressure so that the metal spreads into the groove and is held in place by the undercut. Any exposed metal above the top of the groove is then ground and polished so that the metal is flush with the surface of the stone. One disadvantage of the present method is that the pressure of inlaying the metal wire often cracks or shatters the stone and therefore the method requires the use of high-quality, or synthetic stones. Such high quality stones are expensive and increase the cost of the resulting article. Another disadvantage is that the method requires the time and skill of an experienced craftsman which further increases the cost of such jewelry articles. Also, since this technique utilizes wire as the inlay material, the inlay is necessarily limited to relatively narrow lines.
It is also known in the art to form a metal blank and then glue or rivet the blank into a complementary groove or recessed area formed in a stone. Although this inlay method works, the metal blanks do not always fit tightly within the recessed area and leave gaps between the metal and stone, thus detracting from the aesthetic value of the final product. Foils have also been fixed in grooved areas, however the foil lies below the surface of the stone and detracts from the appearance thereof.
Heretofore, methods have been known for depositing a thin metal film on the surface of a non-conductive material. In this regard, the U.S. Pat. Nos. to Scharling No. 472,230 and Franklin No. 1,037,887 represent the closest prior art to the present invention of which the applicant is aware. The Scharling patent discloses a method of depositing metals onto a glass or other non-conductive surface. The method comprises applying an adhesive substance to the surface, coating the adhesive with a metallic powder, and then electroforming a thin coating of metal onto the powder. The patent to Franklin discloses a similar process of plating metals onto non-conducting surfaces. This particular method comprises applying a sticky varnish material to the surface of the article, coating the varnish with a powdered graphite, and then electroplating the metal onto the surface, using the graphite as a cathode in the plating bath. However, none of these methods relate to an inlay process.